说明：  基于DES加密算法的二进制加密解密程序，内含主程序与加密函数、解密函数，有详细注释，并画出了二进制信号波形。
(DES encryption algorithm based on binary encryption and decryption process, containing the main program and the encryption function, decryption function, detailed notes, and draw a binary signal waveforms.)